Over 7 million people worldwide (around 400,000 in the U.S.) die annually from rhythm disorders of the heart. Many more people are disabled each year from such rhythm disorders. Despite these alarming statistics, the development of a noninvasive imaging modality for cardiac arrhythmias to help physicians identify patients at risk of sudden death, provide specific diagnoses, and guide therapy has only recently borne fruit.
Previous works by one of the inventors herein in the field of noninvasive ECGI are represented by U.S. Pat. No. 6,772,004, entitled “System and Method for Non-Invasive Electrocardiographic Imaging” pending U.S. patent application Ser. No. 10/264,572, filed Oct. 4, 2002, entitled “System and Methods for Noninvasive Electrocardiographic Imaging (ECGI) Using Generalized Minimum Residual (GMRES)” now U.S. Pat. No. 7,016,719), and pending U.S. patent application Ser. No. 10/317,953, filed Dec. 12, 2002, entitled “Systems and Methods for Determining a Surface Geometry” now U.S. Pat. No. 6,975,900), the entire disclosures of all of which are incorporated herein by reference. These works disclose the computation of epicardial cardiac surface potentials, electrograms, and isochrones from noninvasively-measured body surface potentials using, in part, a technique known as the Boundary Element Method (BEM). For ease of reference, the technology disclosed in these applications will be referred to as BEM ECGI hereinafter. With BEM ECGI, 3D surface meshes of a patient's torso surface and epicardial cardiac surface are created to compute a matrix of coefficients A for translating measured body surface potentials to epicardial cardiac surface potentials (which in turn can be translated into electrograms and/or isochrones). This 3D surface meshing is an iterative time-consuming task that requires large memory resources. The BEM ECGI process is further slowed by the manual optimization of the surface meshes that is generally required to maintain accuracy in reconstructing the epicardial cardiac surface potentials. Meshing generally involves the definition of triangular-shaped elements (or elements of other shapes) that together define a 3D boundary around a surface of interest. Software can be used to initially automatically create the 3D surface mesh. However, this initial mesh will often need to be optimized to improve its accuracy, thereby further adding to the time required to accurately reconstruct the surface potentials and, in turn, further detracting from BEM ECGI's applicability to clinical applications. Moreover, the skill level required to optimize body surface and heart surface meshes is generally high, which limits the pool of people who are qualified to conduct BEM ECGI. Further still, even with a skilled person performing mesh optimization, it is believed by the inventors herein that BEM meshes nevertheless exhibit difficulty in accommodating complex heart geometries (particularly concave geometries) such as those that may be found in patients suffering from heart disease.